Evaluación del proceso de extracción alcalina de bixina de semillas de achiote (Bixa orellana)

Abstract

Bixin is a natural colored compound found in the seeds of annatto (Bixa orellana) which corresponds to the carotenoid present in bigger proportion and is of great interest for the chemical, cosmetic, food and pharmaceutical industry [1],[2]. In this work the extraction of bixin from the seed of annatto was evaluated using three diluted bases: sodium hydroxide (NaOH), potassium hydroxide (KOH) and triethalonamine (TEA). It was determined that when the alkali of the extraction was varied the average yields were: 4.27 ± 0.12% (NaOH), 5.26 ± 0.31% (KOH) y 1.81 ± 0.16% (TEA). In addition, the purity degree was identified for each base, obtaining values of 1.95 ± 0.55 ppm, 2.05 ± 0.50 ppm y 1.74 ± 0.24 ppm, respectively. Subsequently, the extraction varying the state of the seed was studied, in order to determine the yield and purity of the obtained bixin. For this, KOH was used as the alkali according to previous results. This allowed to establish that the extraction processes starting with milled seed, allow larger yields that the ones achieved with whole seed. Obtaining average yield values of 35.36 ± 0.44% y 4.30 ± 0.12%, correspondingly. Additionally, the effect of the initial state of the seed on the purity value of the extracted metabolite was evaluated, registering concentrations of 0.80 ± 0.11 ppm (milled seed) y 0.99 ± 0.12 ppm (whole seed). This variation presented was not statistically significant, so the whole seed was considered as the ideal state for bixin extraction processes. The physicochemical characteristics of the metabolite were determined, obtaining a melting point of 220°C, a biomass percentage of 79.40% and a humidity percentage of 10.60%; developing research using instrumental technics of UV-Visible spectroscopy, infrared spectroscopy (FT-IR) and high performance liquid chromatography (HPLC).